Fluid instability analysis developed for the growth or decay of large, longitudinal roller vortex perturbations imposed at the base of fluids of exponentially stratified viscosities is presented. The origin of longitudinal grooving and fluting in a region of converging flow in Tiu Vallis, Mars, is analyzed, and the propensity of fluids, such as water, mudflow/debris flow, and lava, to develop longitudinal roll patterns as part of their flow field is tested. It is found that the grooving pattern in Tiu Vallis was probably formed by vortex motion in a mudflow or debris-laden slurry, but exact representation of sediment/debris concentration or sediment transport machanism is not yet possible. It is concluded that longitudinal vortex motion modelled in this analysis can develop in water, lava, or ice, but that the specific flow characteristics of these models which include the vortex motion are unreasonable for flow in Tiu Vallis.
LUNAR AND PLANETARY EXPLORATION
Geophysical Research Letters; 6; Sept